JP3270713B2 - Method and apparatus for producing metal powder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk rotating at a high speed, and a crushed body or a sliding member disposed so as to correspond to a metal powder discharge portion of the disk.
The present invention relates to a method and apparatus for producing a large amount of fine metal powder from molten metal using a pot- like crushed body.

[0002]

2. Description of the Related Art As one of the methods for producing a large amount of metal powder, it has been generally practiced to rapidly cool a molten metal into fine particles (= atomizing method). However, in this atomization method, granulation is performed using single-stage splitting during rapid cooling, so granulation only depends on the surface tension of each molten particle at the time of splitting. Are necessarily irregular and the particle size distribution has to be spread over a wide range. Therefore, it is unavoidable that particles having a large particle size are mixed in the fine particles.

FIG. 9 shows the particle size distribution of the powder by the atomizing method. According to this, the peak reaches around 40 to 55 μm, and the ratio of this portion to the whole is about 20%. As shown in FIG. 14 (1), the average particle size is 42 μm.
m. The coarse particles are of the order of 150 μm, and the fine particles are of the order of 5 μm, the distribution of which is very wide, and coarse particles and fine particles are mixed. Therefore,
If a powder having a desired particle size is to be obtained, a classification process must be performed after the generation of the powder to select only the powder having the desired particle size. As a result, the yield of the powder product having the desired particle size decreases. However, there is a problem that the manufacturing cost is increased. As a further major disadvantage, as described above, fine powder could not be obtained, and only those having an average particle size of about 40 to 55 μm could be obtained.

Accordingly, the inventors have disclosed in Japanese Patent Application Laid-Open No. Hei 8-2092.
No. 07 proposed a method for producing a metal powder. That is, a liquid film (40) of the dispersing refrigerant (30) flowing on the surface of the rapidly rotating disk (19) is formed, and the liquid film (40) has a small flow of the molten metal (30) or a gas-atomized fine liquid. The droplets (60) are continuously supplied and split into fine particles to form a metal powder. This allows
Although the problems of the conventional rapid cooling method have been solved to some extent, the powder (90) has not been sufficiently refined and its particle size distribution has been wider and less than the target. In addition, metal powder adheres and accumulates on the surface of the disc (19) due to prolonged use, and if this is peeled off and mixed in, large particles will be mixed in the fine powder (90), making continuous operation for a long time impossible. There was a problem that it was possible.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of such a conventional example, and maintains substantially uniform particle size distribution of the obtained metal powder (including an amorphous alloy) in a narrow range. The problem to be solved is to produce powder with a diameter and a spherical particle shape, and to prevent the fine powder that has been pulverized onto mechanical pulverization means such as disks and pulverized bodies from adhering and accumulating one after another. I do.

[0006]

According to a first aspect of the present invention, there is provided a method of manufacturing a metal powder, comprising the steps of:
A liquid film (4) of the refrigerant (3) flowing on the surface of (1) is formed, a molten metal (2) is supplied to the liquid film (4), and the molten metal (2) is liquid film (4). After quenching and miniaturizing with the disc (1)
The metal powder (9) is discharged from the disk (1) together with the liquid film (4) by the centrifugal force of the disk (1), and the pulverized body (10) disposed so as to correspond to the metal powder release portion (1b) of the disk (1) is formed. A method for producing metal powder by crushing and crushing a metal powder (9) , comprising:
The metal powder crushing surface of the crushed body (10) surrounding (1) is
The inner and outer metal powder crushing surfaces are opposite to each other
It is shaped like a mortar, and the inner metal powder crushed surface
The edge is in the outer metal powder grinding surface ".

According to this, as a first stage of pulverization, a molten metal (2) supplied as a fine stream is supplied to a liquid film (4) of a refrigerant (3) flowing on the surface of a rotating disk (1). Is divided into fine powder upon contact. That is, since the liquid film (4) flowing due to the centrifugal force of the disk (1) is moving relatively to the molten metal (2) entering therein, the liquid film (4) first moves to the liquid film (4). The part that has entered is sheared away from the part that has not yet entered and is allowed to flow as it is, forming separate particles. However, in this case, the granulation only depends on the surface tension of each molten particle at the time of splitting as described above, so that the particle size is necessarily irregular and the particle size distribution is spread over a wide range. But,
Here, since the formed particles are in a state of being dispersed in the refrigerant (3), it is possible to prevent the refrigerant (3) from being filled between the particles and the particles from adhering again to form large particles. If a liquid having a large heat capacity is used as the refrigerant (3), heat is rapidly removed from the molten metal (2), so that the cooling rate can be increased, which is effective, for example, for producing an amorphous metal powder (9). . disk
Examples of the refrigerant (3) supplied to the surface of (1) include liquid carbon dioxide, water, Bertrel, liquid nitrogen, industrial oil, liquid oxygen, and organic solvents. As shown in FIG. 2, the molten metal (2) supplied to the surface of the rotating disk (1) instantaneously bounces in the tangential direction of the metal powder discharge site (1b) due to the centrifugal force of the disk (1). At this point, it is considered that only the surface portion of the particles has been solidified by cooling.

[0008] As a second stage of the subsequent pulverization, the powder is further pulverized by colliding with a pulverized body (10) arranged so as to correspond to the metal powder discharge site (1b) of the disk (1). However, in the embodiment shown in FIGS. 1 to 5 and FIG. 8, one or more metal powders are formed by a cylindrical or mortar-shaped pulverized body (10i) arranged so as to surround the disk (1). Examples of the pulverized body (10i) having a pulverized surface are shown in FIGS.
(10ii) shows an example of a pulverized body (10ii) having metal powder pulverized surfaces (10iia) (10iib) of a plurality of layers (not shown, but naturally includes a single layer). Alternatively, branch symbols (i) and (ii) are added to (10) when the metal powder crushed surface is distinguished, and is displayed without a branch symbol when there is no need to distinguish.

In the embodiment shown in FIGS. 1 to 5 and FIG.
A mortar-shaped crushed body disposed so as to surround the periphery of (1)
In (10i), a pulverized body (10
i) Metal powder pulverized surface (10ia) <If the metal powder pulverized surface is multiple, it will collide with (10ib) (10ic) ...> one after another and be further pulverized. Is a disk-shaped crushed body (10i
i), a pulverized body (10i
The metal powder pulverizing surface (10iia) of (i) << If the metal powder pulverizing surfaces are multiple, they collide with (10iib) ... >> one after another and are further pulverized.

In this case, the powder (9) taken out from the pulverized body (10) is not only extremely finely pulverized but also contained in the powder (9) discharged from the disk (1) as compared with the conventional example. Large mixed particles have a large mass and an unsolidified portion at the center, so that the impact force when hitting the pulverized body (10) is large, so that the particles are effectively finely pulverized. On the other hand, the impact force at the time of the collision of the fine particles is small, and the particles are hardened to a fine size because they are solidified to a certain extent to the central portion. As a result, not only the average particle size is reduced, but also the ratio of large particles being preferentially and effectively pulverized and mixed with the fine particles is drastically reduced, and powder having a smaller average particle size and a narrow particle size distribution as a whole is obtained. (9) will be obtained.

Here, the installation direction of the disk (1) is generally a horizontal direction (of course, the installation direction is not limited, and it goes without saying that the disk (1) may be vertical or oblique). Single cylindrical pulverized body such as 2 (10
In the case of (i), the metal crushing surface (10ia) is disposed at right angles or at an angle (not shown) with respect to the disk (1), and the mortar (10i) as shown in FIGS. ) For multiple
The metal crushing surfaces (10ia), (10ib), (10ic)... Are arranged to be inclined with respect to the disk (1). Metal crushed surface (10ia) (10ib)
The edges of (10ic)… overlap each other, and the metal powder (9) released from the edges of the metal crushing surface (10ia) (10ib) (10ic)… collides with the outer metal crushing surface It is supposed to.

On the other hand, in the case of the disk-type crushed body (10ii), as shown in FIGS. 6 and 7, the metal crushing surface (10iia) is formed so as to correspond to the metal powder discharge site (1b) of the disk (1). (Ten
iib) is arranged obliquely with respect to the disk (1). Of course, although not shown, a disc-shaped pulverized body (10i
i) into one piece, and the metal crushed surface (10iia) into a disc (1)
May be disposed at right angles or at an angle to the device.

[0013] The pulverized body (10) may be fixed or rotated, regardless of whether it is a mortar type or a disk type.
When rotating, it may be in the same direction as the disc (1) or in the opposite direction. In the opposite direction, the relative speed is higher, and pulverization is more effectively performed.

The disc (1) is generally of a disk type as shown in FIG. 1, but is of an inverted cone type or inverted conide type (inverted Mt. Fuji type) as shown in FIG. Also, there are various types such as those having an umbrella-shaped surface as shown in FIG. In the case of FIG. 6, the heat capacity of the disk (1) increases,
It is difficult to be heated by the supplied molten metal (2) or fine droplets (6), and in the case of FIG. 8, it is easy to discharge the coarse powder (9) generated on the surface of the disk (1) in the horizontal direction .

[0015] The material of the disc (1) and grinding bodies (10) may be formed across a metal powder deposition inhibiting material such as ceramic or polymeric materials, disks as described in "5." The surface of (1) and the crushed surface of the pulverized body (10) (10a)
<< (10b) (10c) >> may be coated with a metal powder deposition preventing material. In this case, it is possible to prevent the finely divided metal powder (9) from adhering and depositing on the surface of the disk (1) or the crushed metal surface (10a) of the crushed body (10), and it is possible to efficiently reduce the size of the powder. At the same time as possible, it is possible to prevent the deposited and enlarged metal particles from coming off and being mixed into the fine powder (9). It is considered that the reason why the adhesion is difficult is related to the wettability between the ceramic or polymer material and the molten metal, or the heat capacity and the thermal conductivity of the ceramic or polymer material. When the metal powder deposition preventing coating layer (12) is present, the adhesion of the metal powder (9) is reduced as compared with the case where the disk (1) and the pulverized body (10) are formed of metal. The metal of the pulverized body (10i)
When the shattering surface (10ia) is cylindrical, as shown in FIG.
Heavy, and the metal crushing surface (10ia) (10ib) (10
ic)... are nested when they are in the shape of a mortar. Any
Even when the powder (9) released from the pulverized body (10i)
Shattering surface (10ia) 《(10ib) (10ic)…》
However, it is finer and more granular
The degree distribution becomes narrow. That is, the metal powder (9) is pulverized multiple times.
Metal powder crushed surface of body (10i) (10ia) (10ib) (10ic) ... one after another
At the same time, the particles are gradually refined by collision and large particles
At the same time as grinding at any stage and extremely fine
The particle size of the powder (9) is extremely uniform. Also powder
The crushed metal surface of the crushed body (10) (10ia) << (10ib) (10ic)… >>
The case where it is stopped and the case where it is rotating as described later
Yes, if it is stopped, it will be
Rolls along the broken metal surface (10ia) without scattering
Will fall and be discharged.

In a second embodiment, the second aspect is that a liquid film (4) of the flowing refrigerant (3) is formed on the surface of the rotating disk (1), and the liquid film (4) The droplet (6) of (2) is supplied, and the droplet (6) of the molten metal (2) is quenched and refined by the liquid film (4), and then the liquid film is formed by the centrifugal force of the disk (1). (4) The metal powder (9) is released from the disk (1) together with the pulverized body (1) disposed so as to correspond to the metal powder release site (1b) of the disk (1).
0) to be a pulverized by colliding a metal powder (9), di
The pulverized body (10) surrounding the disc (1)
And the inner and outer metal powder crushing surfaces are mutually
It is formed in a mortar shape in the opposite direction, and crushes metal powder inside
The edge of the surface is within the outer metal powder grinding surface . "

This case is basically the same as the first aspect, except that a fine droplet (6) formed by, for example, gas atomization is supplied instead of supplying a small flow of the molten metal (2). . According to this, for example, the molten metal (2) is divided and finely divided into fine droplets (6) by gas atomization, and the fine droplets (6) collide with the disk (1) by jetting gas at the time of gas atomization and furthermore. It is quenched by a liquid film (4) of a coolant (3) which is crushed and flows on the surface of the disk (1). Also, in the case of the large droplets (6), the splitting and pulverizing mechanism according to claim 1, that is, the liquid of the refrigerant (3) flowing on the surface of the rotating disk (1) simultaneously with the pulverization by the collision. It is also conceivable that the fine particles are further divided into fine particles upon contact with the membrane (4). In this way, the first stage of finer refinement is performed at the disk (1) stage than in the case of the first aspect.

As a second stage of the subsequent miniaturization, the powder (9) discharged from the disk (1) in the tangential direction by centrifugal force was arranged so as to surround the periphery of the disk (1). Metal crushing surface of a mortar-shaped crushed body (10i) (10ia) << (10ib)
(10ic)… »or a disc-shaped crushed body (10i
It is further pulverized by colliding with the metal crushing surface (10iia) << (10iib)...) of i), and this point is the same as in claim 1. Also, the installation direction of the disc (1), the crushed body (10)
The same applies to the direction and the number of the metal crushing surfaces (10a), the presence or absence of rotation, the rotation direction, and the type of the refrigerant (3) supplied to the surface of the disk (1). When the gas atomization method is used to form the molten metal (2) into droplets in claim 2, the spray gas for forming the fine droplets (6) of the molten metal (2) is generally argon or nitrogen. An inert gas such as is used.

A third aspect of the present invention is directed to an apparatus for producing a metal powder for carrying out the method according to the first aspect, wherein the apparatus comprises a rotatable disk (1) and a coolant (3) on a surface of the disk (1). A molten metal supply unit (7a) for supplying molten metal (2) toward the surface of the disk (1), and a disk (1).
The disk is arranged corresponding to the metal powder discharge area (1b)
Metal powder (9) released together with the liquid film (4) by the centrifugal force of (1)
And a crushed body (10) with which the metal powder collides.
And the metal of the crushed body (10) surrounding the disc (1)
The powder grinding surface is formed with multiple layers, and the inner and outer metal
The powder crushing surfaces are formed in a mortar shape in opposite directions,
The edge of the inner metal powder grinding surface is within the outer metal powder grinding surface.
That "it is characterized in.

A fourth aspect of the present invention is directed to an apparatus for producing a metal powder for carrying out the method according to the second aspect, comprising a rotatable disk (1) and a refrigerant (3) on a surface of the disk (1). And a molten metal droplet supply unit (7b) for supplying molten metal (2) droplets (6) toward the surface of the disk (1).
And a crushed body (10) arranged corresponding to the metal powder discharge site of the disc (1), and the metal powder (9) discharged together with the liquid film (4) by the centrifugal force of the disc (1) collides with And composed of metal
A powder production device, comprising a crusher surrounding a disc (1).
The metal powder crushing surface of the body (10) is formed with a plurality of layers, and
The inner and outer metal powder crushing surfaces are formed in a mortar shape with the directions opposite to each other
The edge of the inner metal powder crushing surface is the outer metal powder
In the grinding plane ".

Claim 5 relates to the improvement of the apparatus for producing metal powder, wherein at least the surface of the disk (1) and the metal crushed surface (10a) << (10b) (10c)... Either one is coated with a metal powder deposition preventing material. "
According to this, due to the coating layer (12) of the metal powder deposition preventing material, the finely divided metal powder (9) has the surface of the disk (1),
Alternatively, the metal crushing surface of the crushed body (10) (10a) << (10b) (10c)
..} Can be prevented from adhering and accumulating, and the particles can be efficiently pulverized, and at the same time, the particles that have accumulated and become larger can be prevented from peeling and mixing into the fine particles. In the case where multiple metal crushing surfaces are provided, at least one of the surfaces (10a) (10b) (10c).
Finally, a coating layer (12) will be provided.

Further, at least the metal crushing surface (10a) of the crushed body (10) or the final surface when there are multiple metal crushing surfaces.
It is desirable to provide a coating layer (12) on (10c) in order to prevent the entry of coarse particles. It is considered that the reason why it is difficult to adhere / deposit is due to the wettability, heat capacity, heat conductivity, etc. of the two as described above. That is, from the viewpoint of wettability, the metal crushing surface (10a) (10b) of the metal disk (1) or the metal crushed body (10) having no coating layer (12)
(10c) ... generally means that a thin oxide layer is formed on the surface and a liquid film (4) exists on the surface, and the molten metal (2) or molten metal droplet (6) When supplied, the liquid film (4) and the oxide layer may be broken, exposing the metal surface, and the hot molten metal (2) or molten metal droplet (6) may directly contact and adhere to the metal surface If you have a coating layer (12) or disc
When (1) or the crushed body (10) is formed of the same material as the coating layer (12), the supplied molten metal (2) or molten metal droplet (6) has poor wettability to the metal. It is considered that the contact with the surface prevents the adhesion. In addition, since these metal powder deposition preventing materials generally have a larger heat capacity than metals and have poor thermal conductivity, even when they come in contact with a high-temperature molten metal (2) or molten metal droplet (6), the temperature changes. It is considered to be low in adhesion from this surface.

Claim 6 relates to the improvement of a metal powder manufacturing apparatus, wherein the metal powder deposition preventing material is a ceramic.
It is characterized by.

Claim 7 relates to another improvement, “Metal powder pile”.
The stacking prevention material is a polymer material. "

[0025]

[0026]

Claim 8 relates to a further improvement of the pulverized body (10) of the apparatus for producing metal powder.
(10a) << (10b) (10c) ... >> is rotating ". "Claim 9" is based on the improvement of "metal powder
The grinding surfaces are rotating in opposite directions. "
You. Here, in the case where the metal powder crushing surface (10a) is single, the rotation speed of the metal powder crushing surface (10a) with respect to the disc (1) is higher (the rotation direction is more preferably reverse), or
(10) is provided with a plurality of metal powder crushing surfaces (10a) (10b) (10c)...
The higher the rotation speed of the metal powder and the adjacent metal powder grinding surface (10a) (10
b) As the relative rotation speed of (10c)... is higher (the rotation direction is more preferable), the particle size of the metal powder (9) is made finer and uniform.

[0028]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. The invention is of course not limited to the embodiments described below. FIG. 1 shows the basic form of the device of the present invention.
Rotatable disc (1) and coolant on the surface of disc (1)
A refrigerant supply unit (11) that supplies (3), a molten metal supply unit (7a) that supplies molten metal (2) toward the surface of the disk (1),
It is arranged so as to surround the disk (1), and is constituted by a crushed body (10) against which the metal powder (9) released together with the liquid film (4) by the centrifugal force of the disk (1) collides. . In this case, since the crushed surface of the metal powder of the crushed body is cylindrical, the crushed body is indicated by (10i) and the crushed surface of the metal powder is indicated by (10ia).

The disk (1) is, for example, a disk as shown in FIG. 1 (or an inverted cone as shown in FIG. 3), and is rotated around a rotation shaft (13) provided at the center. The rotation speed is not limited to this, but for example, 4,000 rpm to 20,000 rpm
00 rpm (of course, up to about 45,000 rpm is possible). Although the diameter is not particularly limited, it is 400 to 1,000 mm. When the diameter increases, a plurality of molten metal supply units (7a) and a molten metal droplet supply unit are provided.
(7b) can be installed on one disk (1), and productivity can be improved. The installation direction of the disk (1) is generally horizontal. Of course, they may be arranged vertically or inclined. The material constituting the disk (1) may be entirely formed of a ceramic or polymer material which is a metal powder deposition preventing material, or a disk body (1a) formed of a metal material and its necessary surfaces, for example, The composite disk (1) may be constituted by a coating layer (12) in which the surface of the disk body (1a) to which the molten metal (2) is supplied is coated with the material. 1 and 2 show an example in which the disk (1) is composed of a disk main body (1a) formed of a metal material and a coating layer (12) whose surface is coated with the material. As the ceramics, for example, oxides, nitrides, carbides, borides and the like are used. As the polymer material, for example, vinyl chloride resin, vinylidene chloride, vinyl acetate, styrene resin,
Acrylic resin, polyethylene, polypropylene, fluororesin, polyamide resin, polyacetal, polycarbonate, acetylcellulose, wood-based materials and the like are used.

The coolant supply section (11) is a thin nozzle extending obliquely toward the center of the surface of the disk (1) (may be arranged at the center of the disk (1) as shown in FIGS. 4, 6, and 8). The refrigerant (3) supplied from this is, for example, liquid nitrogen,
Liquid carbon dioxide, water, Bertrel, industrial oil, liquid oxygen, organic solvents, etc. The flow rate of the refrigerant (3) is
(2) type, temperature of molten metal (2) (superheated to the melting point of the target metal or alloy in the range of 100 to 500 ° C, preferably 250 to 300 ° C or more), Rotation speed of disk (1), distance from tip of nozzle (8) of molten metal supply section (7a) to disk (1)
(H), which is appropriately selected depending on the supply amount of the molten metal (2).

The molten metal supply section (7a) is, for example, a crucible having a nozzle (8) at the bottom. The nozzle diameter is not limited to this, but in the present embodiment, it is as thin as about 1 mm. The molten metal (2) flows in a thin stream toward the surface of the disk (1).
(Of course, the distance between the outlet of the nozzle (8) and the surface of the disc (1)
When (H) is far, large droplets may be formed due to the surface tension of the molten metal. )

In the case of FIG. 1, a cylindrical pulverized body (10i) is provided so as to surround the periphery of the disk (1). In the case of Fig. 1, the metal powder crushing surface of the crushed body (10i) against the disc (1)
(10ia) is arranged at a right angle.
The grinding body (10i) is rotated in the direction opposite to the rotation direction of the disk (1), with (1) and its rotation center aligned (of course, it is not necessary to match). << Of course, the rotation directions of both may be the same direction, and the pulverized body (10i) may be stopped. The rotation speed of the pulverized body (10i) is of course not limited to this, but may be 100 to 600 rpm (400 rpm in this embodiment).
m), which is lower than the rotation speed of the disk (1).

The metal to be pulverized may be any metal, and is not limited to the following examples. For example, copper, aluminum, stainless steel, ferrosilicon, cobalt, There are various types such as nickel, solder, silver, zinc, FeSiB and other amorphous alloys.

In the case of FIG. 1, the disk (1) is rotated at a high speed, and the refrigerant (3) is supplied from the refrigerant supply section (11) to the disk.
The liquid film (4) of the refrigerant (3) flowing on the surface of the rotating disk (1) supplied to the surface of (1) is formed. The thickness of the liquid film (4) is
It is determined by the type and supply amount of the refrigerant (3) constituting the liquid film (4) and the rotation speed of the disk (1). In this state, the molten metal (2) is supplied to the molten metal supply section (7a), and the molten metal (2) flows down from the nozzle (8) as a thin stream. The molten metal (2) flows down, and the molten metal (2) comes into contact with a liquid film (4) composed of a refrigerant (3) and is miniaturized.

As described above, when the molten metal (2) enters the moving liquid film (4) as described above, the liquid flowing at a high speed together with the disk (1) rotating at a high speed. The part that has entered the liquid film (4) earlier by the membrane (4) is sheared and separated from the part that has not yet entered, and flows as it is. Will form particles. In this case, the liquid film
(4) Because of the splitting and refinement using high-speed flow and rapid cooling, granulation only depends on the surface tension of each particle at that time, and as a result, the particle size distribution of the powder at this point is quite wide. It will spread.

Subsequently, the coarse powder (9a) is discharged at high speed in the tangential direction by centrifugal force together with the refrigerant (3) constituting the liquid film (4) by the high-speed rotation of the disk (1). Collides with the metal powder pulverizing surface (10ia) of the pulverized body (10i) disposed around. The released coarse powder (9a) is not completely coagulated, and the colliding coarse powder (9a) is further refined by the impact force, but here, it is finely pulverized as described above. In addition, large particles have a large mass and contain a large unsolidified part in the center part, so the impact when hitting the metal powder crushing surface (10ia) of the crushed body (10i) Although the force is large and the particles are effectively pulverized, the impact force at the time of the collision of the fine particles is small and the unsolidified portion is small, so that the particles are difficult to be miniaturized. As a result, most of the particles having a large particle diameter are not pulverized and remain little, and the proportion of the particles mixed in the fine particles is greatly reduced.As a result, the powder (9) having a narrow particle size distribution as a whole can be obtained. . Finely divided powder having a narrow particle size distribution and not seen in the past
(9) will be obtained.

When the crushed body (10i) is moving relative to the disk (1) (especially when the rotating directions are opposite to each other), the metal powder of the crushed body (10i) The coarse powder (9a) colliding with the pulverizing surface (10ia) is further finely pulverized mechanically, and at the same time, rolls on the pulverizing body (10i) due to the centrifugal force of the pulverizing body (10i) to form a round granular material having no corners. It becomes a fine powder (9).

In the course of the above miniaturization, the refrigerant (3) not only cools the disk (1) and the molten metal (2), but also wets and adheres around the micronized particles, and It prevents them from re-adhering to one large particle. If a liquid having a large heat capacity is used as the refrigerant (3), heat can be rapidly removed from the molten metal (2) or finely divided particles, so that the cooling rate can be increased, for example, mass production of amorphous metal powder. It is effective for The powder (9) refined by the pulverized body (10i) falls along the pulverized body (10i) and accumulates at the lower part.

Next, a second embodiment will be described. In this case, unlike the first aspect, a fine liquid droplet (6) of the molten metal (2) is supplied to the liquid film (4) using the metal liquid droplet supply section (7b);
The point is that the pulverized body (10i) is a multi-stage (three-stage in the present embodiment) type in a mortar shape. Of course, although not described as an embodiment of the present invention, the molten metal supply unit (7a) and the multi-stage pulverized body (10i)
May be used in combination, or conversely, the molten metal droplet supply unit (7b) and the single-stage pulverized body (10i) may be used in combination.

The metal droplet supply section (7b) is provided with a gas injection nozzle (14) for injecting inert gas around the bottom nozzle (8) as shown in FIG. A gas is injected into the molten metal (2) that has flowed down from 8), and the molten metal (2) is divided and refined immediately after flowing down, and the molten metal (2) is turned into fine molten metal droplets (6).

The fine molten metal droplet (6) collides with the disk (1) by gas injection during gas atomization and is further pulverized, and the same mechanism as that of the first embodiment, that is, the surface of the disk (1) is moved at a high speed. The liquid film (4) is further miniaturized and rapidly solidified at the same time as the flowing liquid film (4), and then the metal powder (9) is tangentially removed from the disk (1) together with the liquid film (4) by the centrifugal force of the disk (1). At a high speed and collide with the metal powder crushing surfaces (10ia), (10ib), and (10ic) of the plurality of crushed bodies (10i) arranged around the disk (1) while being accelerated one after another to be further crushed.

Here, the pulverized surfaces (10ia), (10ib) and (10ic) of the metal powder of the pulverized body (10i) of the present embodiment are inclined with respect to the disk (1), so that the inner and outer pulverized shapes are formed. Are alternately arranged in opposite directions. Then, the first-stage metal powder crushing surface (10ia) and the third-stage metal powder crushing surface (10ic) rotate in the opposite direction with respect to the disk (1), and the second-stage metal powder crushing surface (10ib) ) Rotates in the same direction as the disk (1) so that the relative speed is maximized. In this embodiment, the rotation speed of the metal powder crushing surfaces (10a) (10b) (10c) is 100 to 60 as described above.
About 0 rpm (400 rpm was adopted in this embodiment)
And is slower than the rotation speed of the disk (1). (Note that the rotation direction is not limited to the above-described case, and may be the same direction, or one of them may be stopped.)

As the second stage of miniaturization, a disk
The metal powder crushed surface (10ia) of the innermost layer of the crushed body (10i) arranged so as to surround the periphery of (1) is further pulverized, but is further pulverized. Since the metal powder crushing surface (10ia) is inclined, the coarse powder (9a) having an unsolidified portion in its part that has collided with the metal powder crushing surface (10ia) is further finely crushed by the impact, and Rolled along the slope by the centrifugal force due to the rotation of the powder crushing surface (10ia), spheroidized, accelerated by the centrifugal force and accelerated from the edge of the metal powder crushing surface (10ia) to the metal powder crushing surface (10ia). Released tangentially. The discharged powder (9) collides with the second-stage metal powder crushing surface (10ib), is further pulverized by the same mechanism as described above, and is released tangentially from the edge thereof, and the third-stage metal powder crushing surface (10ib). 10ic). The metal powder is further pulverized by the same mechanism on the third-stage metal powder pulverized surface (10 ic) and then released in the tangential direction. As a result of such multi-stage pulverization, an extremely fine powder (9) having a small particle size distribution width is obtained.

Here, the disk (1) itself, the surface of the disk (1), and each metal powder crushing surface (10i) of the crushed body (10i)
a) (10ib) (10ic) is coated with a coating layer (1
2), the metal powder is
Hardly adheres or accumulates on the surface of (1) or on the pulverized surface of each metal powder (10ia) (10ib) (10ic). Hardly mixed into the fine powder (9).

Here, the average particle size of various metals by the conventional atomizing method and the method of the present invention [slurry bowl type three-stage pulverized product (10
3 shows a comparison table of the average particle size of the metal produced according to i)]. Rotation speed of the disc (1) is 12,000 rpm, crushed
The rotation speed of (10) is 200 rpm, and the diameter of the disc (1) is 4
00 mm. According "Comparison 1" to this alloy Cu 42μm 7μm Al 38μm 7μm SUS304 45μm 9μm Fe 94 Si 6 43μm 9μm Co 44μm 8μm Ni 44μm 8μm solder 37μm 6μm FeSiB 44μm 9μm Ag 45μm 8μm Zn 39μm 7μm, the present invention method [Surihachi 3-stage crushed mold (10
It can be seen that the average particle size of the powder produced according to i)] is significantly finely pulverized as compared with the case of the conventional atomizing method.

Next, the particle size distribution in the case of pulverization by the conventional gas atomization method alone (see FIG. 9) and the particle size distribution in the case of pulverization by the combination of the gas atomization method and the disk (disclosed in JP-A-8-209207) Production method of metal powder prepared in the present invention (see FIG. 10), particle size distribution in the case of the present invention which is a combination of a gas atomization method, a disk and a one-stage mortar (see FIG. 11), and three-stage mortar in the present invention 13 shows the particle size distribution in the case of a body (see FIG. 12).
The metal used is copper. In the figure, the vertical axis represents the ratio (%) of each particle size to the whole, and the horizontal axis represents the particle size (unit = μm). According to this, in the case of FIG.
The peak is from 40 μm to 55 μm at μm to 150 μm. In the case of FIG. 10, the particle size distribution is 0.2 μm to 70 μm.
m, its peak is between 10 μm and 15 μm. In the case of FIG. 11, the particle size distribution is 0.15 μm to 50 μm, and the peak is 9 μm to 13 μm. In the case of FIG. 12, the particle size distribution is 0.15 μm to 30 μm, and the peak is 8 μm to 1 μm.
2 μm. From the above, when the table and FIGS. 9 to 12 are taken into consideration, the powder according to the present invention is finer and finer than the conventional powder, and at the same time, the mixing of particles having a large particle size is very small. In particular, in the case of only the atomizing method, classification was necessary to make the particle size necessary, but in the present invention, classification is not necessary.

Next, the effect on miniaturization of the mortar-shaped pulverized body (10i) will be verified. In FIG. 13, a solid line is a broken line indicated by a dash-dot line in the middle stage in a case where fine droplets (6) formed by the gas atomization method are supplied to the rotating disc (1) to be miniaturized. When the fine droplets (6) formed by the gas atomization method are supplied to the rotating disk (1) to be finely divided and further crushed by a single-stage mortar-shaped crushed body (10i), the dashed line at the bottom is the present invention. In another method, fine droplets (6) formed by a gas atomization method are supplied to a rotating disk (1) to be finely divided, and further crushed by a three-stage mortar (10i). The vertical axis represents the particle diameter (μm), and the horizontal axis represents the rotation speed (rpm) of the disk (1). The rotation speed of the pulverized body (10i) is fixed at 200 rpm, and the diameter of the disk (1) is 400 mm. According to this, regardless of the presence or absence of the pulverized body (10i), the higher the number of revolutions of the disk (1), the smaller the average particle size, but the one with the pulverized body (10i) and the one with more stages It can be seen that the size is further reduced.

FIG. 14 shows another verification example of the effect on the pulverization of the pulverized product (10). The vertical axis represents the average particle size of the powder, and the horizontal axis represents [1].
In the case where only the conventional gas atomization method is used, the case where the gas atomization method and the disc are combined in [2] is [3]
In the case of combining a gas atomizing method as an example of the present invention with a disc and a one-stage mortar-shaped crushed body in [a], a gas atomizing method and a disc with another example of the present invention in [3b] are shown in [3b].
A case was taken in combination with a pulverized body in the shape of a terraced pot.
The average particle size in [1] is 42 μm, the average particle size in [2] is 10.2 μm, the average particle size in [3a] is 9.2 μm, and the average particle size in [3b] is The average particle size in this case was 7.8 μm. Copper was used as a sample, the rotation speed of the disk (1) was 12,000 rpm, the rotation speed of the pulverized body (10) was 200 rpm, and the diameter of the disk (1) was 400 mm.
It is. According to this result, it is apparent that the use of the pulverized body (10i) promotes pulverization. However, the finer the more the pulverized body means,
It can be seen that the effect gradually increases when three or more stages are set.

Next, another example of the pulverized body (10ii) will be described with reference to FIGS. The pulverized body used in this case is a disc and is indicated by (10ii). As can be seen from FIG.
When the molten metal (2) or the molten metal droplet (6) is supplied to (1), the molten metal is instantaneously discharged out of the disk (1) by the centrifugal force of the rotating disk (1). The metal powder release site (1b) is the disk (1)
, The heating temperature of the molten metal (2) or the molten metal droplet (6), the thickness of the liquid film (4), and other factors. Therefore, if the crushed body (10ii) is disposed at a position corresponding to the metal powder discharge site (1b), the coarse powder (9a) released from the disk (1) collides with the crushed body (10ii) substantially. And further crushed.

In the embodiment shown in the figure, an example in which two pulverized bodies (10ii) are provided is shown, but it is needless to say that only one pulverized body (10ii) may be provided or three or more pulverized bodies may be provided. The location where the released coarse powder (9a) collides is a position away from the center of the pulverized body (10ii), after the collision,
Released from the crushed body (10ii).

A plurality of disc-shaped pulverized bodies (10ii) are
When disposed near (1), the pulverized body (10iia) closest to the disk (1) is the metal powder discharge site (1b) of the disk (1).
The crushed body on the far side is arranged so as to correspond to the metal powder discharge site of the crushed body on the side closer to the disk (1) as the distance from the disk (1) increases. By doing so, the metal powder (9) pulverized by the pulverized body closer to the disk (1) is sequentially released toward the pulverized body farther away, and further pulverized. Therefore, the metal powder (9) having a finer and narrower particle size distribution can be obtained as in the case of the multiple mortar type. The tendency of the powder (9) obtained is the same as in the case of the mortar-shaped crushed body (10i). When the crushed body (10ii) is a disk, the crushed body (10ii) can be rotated about its rotation axis (16), so that high-speed rotation is easier than that of the mortar-shaped crushed body (10i).

[0052]

According to the present invention, by using a pulverized body, large particles can be pulverized preferentially and effectively, and the ratio of large particles mixed with fine particles can be reduced. Thus, a powder having a fine overall size and a narrow particle size distribution can be obtained. In addition, by coating the surface of the disk and / or the surface of the pulverized body with the metal powder crushing material with a metal powder deposition preventing material, it is possible to efficiently pulverize the particles, and at the same time, the particles that have become larger due to deposition are peeled off and the fine particles are removed. Can be prevented from being mixed in. In addition, by forming the crushed metal crushing surface in a mortar shape and inclining with respect to the surface of the disk, the finely divided powder is dropped while rolling along the metal crushing surface, and its shape is reduced. Can be made spherical. In addition, by forming the metal powder crushing surface of the pulverized body with a plurality of layers, the metal powder collides with the metal powder crushing surface several times one after another and gradually becomes finer, and at the same time, large particles are formed at any stage. The resulting powder is extremely fine and the particle size of the resulting powder is extremely uniform. Further, by rotating the pulverized surface of the metal powder of the pulverized body, more pulverization energy can be given to the metal powder to perform finer pulverization.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram when a single-stage mortar-type crushed body that is a first embodiment of the present invention is used.

FIG. 2 is a plan view of FIG. 1;

FIG. 3 is an enlarged view of a state in which molten metal is supplied to a disk from a nozzle in the apparatus of FIG. 1;

FIG. 4 is a schematic configuration diagram when a three-stage mortar-type crushed body according to a second embodiment of the present invention is used.

FIG. 5 is an enlarged view of a state in which molten metal is supplied to a disk from a nozzle in the apparatus of FIG.

FIG. 6 is a schematic configuration diagram when a two-stage disc-shaped crushed body that is a third embodiment of the present invention is used.

FIG. 7 is a plan view of FIG. 6;

FIG. 8 is a schematic configuration diagram of a modified example of the second embodiment of the present invention, in which the surface of the disk is umbrella-shaped;

FIG. 9 is a particle size distribution table of powder formed only by a conventional gas atomizing method.

FIG. 10 is a particle size distribution table of powder formed by a combination of a conventional gas atomizing method and a disk.

FIG. 11 is a table of particle size distribution of powder formed by a combination of the gas atomizing method according to the present invention, a disk and a one-stage mortar type pulverized body.

FIG. 12 is a table of particle size distribution of powder formed by a combination of the gas atomizing method according to the present invention, a disk and a three-stage mortar-type pulverized body.

FIG. 13 shows a case where a stepping pot type crushed body is used in the present invention,
Comparison table of particle size distribution at each rotation speed of the disc when no pulverized body is used in the conventional example

FIG. 14 shows the average particle size of the powder formed only by the conventional gas atomization method, the average particle size of the powder formed by the combination of the conventional gas atomization method and the disk, and the first and third stages of the gas atomization method and the disk according to the present invention. Comparison table of average particle size of powder formed in combination with mortar

FIG. 15 is a schematic configuration diagram of a conventional apparatus.

FIG. 16 is another schematic configuration diagram of a conventional device.

[Explanation of symbols]

 (1) Disc (2) Molten metal (3) Refrigerant (4) Liquid film (5) High-pressure gas (6) Fine metal droplet (7a) Molten metal supply (7b) Molten metal Droplet supply unit (8) Nozzle (9) Metal powder (10) Pulverized body (11) Coolant supply unit (12) Coating layer (13) Rotating shaft (14) Gas injection nozzle

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Noboru Sato 7-4 Atagocho, Koriyama-shi, Fukushima Prefecture (72) Inventor Oshin Satoshi 4-6-202, Shinsakacho, Aoba-ku, Sendai, Miyagi Prefecture (72) Inventor Yuji Ogata 3-16-8 Tomigaoka, Tomiya-cho, Kurokawa-gun, Miyagi Prefecture (56) References JP-A-8-209207 (JP, A) JP-A-7-54019 (JP, A) JP-A-62-112709 (JP, A) A) JP-A-59-159903 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B22F 9/10

Claims (9)

(57) [Claims] 1. A liquid film of a flowing refrigerant is formed on the surface of a rotating disk, a molten metal is supplied to the liquid film, and the molten metal is rapidly cooled and miniaturized by the liquid film. The metal powder is released from the disk together with the liquid film by force, and the metal powder is crushed by colliding the metal powder with a pulverized body arranged to correspond to the metal powder release portion of the disk.
In the method for producing a metal powder, the pulverized surface of the pulverized metal
The inner and outer metal powder crushing surfaces are opposite to each other
It is shaped like a mortar, and the inner metal powder crushed surface
An apparatus for producing a metal powder, wherein an edge is in an outer metal powder crushing surface . 2. A liquid film of a flowing refrigerant is formed on the surface of a rotating disk, droplets of a molten metal are supplied to the liquid film, and the droplets of the molten metal are rapidly cooled and miniaturized by the liquid film. After that, the metal powder is released from the disk together with the liquid film by the centrifugal force of the disk, and the metal powder is caused to collide with a pulverized body disposed so as to correspond to the metal powder release portion of the disk.
In the method for producing a metal powder to be pulverized, the pulverization surface of the pulverized body surrounding the disc has a plurality of pulverized surfaces.
The inner and outer metal powder crushing surfaces are opposite to each other
It is shaped like a mortar, and the inner metal powder crushed surface
An apparatus for producing a metal powder, wherein an edge is in an outer metal powder crushing surface . 3. A rotatable disk, a refrigerant supply unit for supplying a refrigerant to a surface of the disk, a molten metal supply unit for supplying a molten metal toward the disk surface, and a metal powder discharge portion of the disk. And a pulverized body which is disposed and pulverized by collision of the metal powder discharged together with the liquid film by the centrifugal force of the disk.
Te, metal powder grinding surface of the grinding bodies surrounding the disk at a plurality Weight
The inner and outer metal powder crushing surfaces are opposite to each other
It is shaped like a mortar, and the inner metal powder crushed surface
An apparatus for producing a metal powder, wherein an edge is in an outer metal powder crushing surface . 4. A rotatable disk, a refrigerant supply for supplying a refrigerant to the surface of the disk, a molten metal droplet supply for supplying droplets of molten metal toward the surface of the disk, and discharging metal powder from the disk It is arranged corresponding to the part,
A metal powder made up of a crushed body that is crushed by collision of metal powder released with the liquid film due to the centrifugal force of the disc .
In the manufacturing equipment, the metal powder crushing surface of the crushed body surrounding the disk
The inner and outer metal powder crushing surfaces are opposite to each other
It is shaped like a mortar, and the inner metal powder crushed surface
An apparatus for producing a metal powder, wherein an edge is in an outer metal powder crushing surface . 5. The apparatus for producing metal powder according to claim 3, wherein at least one of the disk surface and the metal crushing surface of the crushed body is coated with a metal powder deposition preventing material. 6. The metal powder deposition preventing material is ceramic.
The apparatus for producing a metal powder according to any one of claims 3 to 5, wherein the apparatus is a metal powder. 7. The polymer powder deposition preventing material is a polymer material.
The apparatus for producing a metal powder according to any one of claims 3 to 5, wherein 8. The metal powder crushing surface of the crushed body is rotated.
The apparatus for producing metal powder according to any one of claims 3 to 7 , wherein: 9. The metal powder crushing surfaces of the crushed body are opposite to each other.
The apparatus for producing metal powder according to any one of claims 3 to 7 , wherein the apparatus is rotated during rotation .